How to Beat Jevil in Deltarune

Who Is Jevil?

Jevil is the former Court Jester of the Card Kingdom. After meeting a "strange someone," he came to believe the entire world is a game and was locked away in the castle basement for the safety of others. He is the first optional secret boss in Deltarune and is widely considered one of the hardest fights in the game.

How to Unlock Jevil

To fight Jevil, you must collect three broken key pieces and forge the Door Key.

1. Talk to Seam in the Field of Hopes and Dreams about the strange prisoner in Card Castle. This starts the quest.
2. Broken Key Piece A: Found in the Field area. Seam points you toward it.
3. Broken Key Piece B: In the Forest area with dancing Paper Dancers, slip onto the hidden dark path to the south-west and defeat the Rabbicks to open the chest.
4. Broken Key Piece C: North of the Field, past a Jigsawry battle. Solve the suit-symbol puzzle in the order shown on Card Castle's floors: Diamond, Heart, Club, Spade.
5. Take all three pieces to Smith Malius at the Bake Sale. He will forge the Door Key.
6. Return to Card Castle and take the south-eastern elevator to the "??????" floor. Use the Door Key on Jevil's cell.

Combat Strategies

Jevil has two victory conditions, like most Deltarune bosses: deplete his HP to zero, or raise his Tiredness and cast Pacify.

Pacifist Strategy (Recommended for First Clear)

• Use Kris's Hypnosis and Pirouette actions to raise Jevil's Tiredness.
• Jevil becomes Tired at Tiredness level 9. Once he is Tired, use Ralsei's Pacify spell to end the fight.
• Hypnosis raises Tiredness more consistently. Pirouette has random effects, some of which raise Tiredness and some of which heal or change Jevil's behavior.
• Defend and heal often. Jevil's attacks are relentless, and survival is more important than speed.

Violent Strategy

• Focus on attacking with Kris and Susie every turn.
• Use Ralsei for healing and boosting defense when needed.
• Susie's Rude Buster deals significant damage if you have enough TP.
• This strategy is faster but more dangerous because Jevil stays aggressive.

Jevil's Attack Phases

Jevil's behavior changes based on his remaining HP and Tiredness. The fight is divided into roughly five phases, each introducing new attack patterns:

• Phase 1: Basic club and diamond attacks. Learn the bullet patterns.
• Phase 2: Triggered at ~80% HP or Tiredness 2. Faster attacks and more projectiles.
• Phase 3: Triggered at ~60% HP or Tiredness 4. Jevil says "METAMORPHOSIS!" and transforms.
• Phase 4: Triggered at ~40% HP or Tiredness 6. Chaotic patterns and Devilsknife summons.
• Phase 5: Triggered at ~20% HP or Tiredness 8. Jevil uses his ultimate "Final Chaos" attack. Survive this to win.

Jevil's attacks are not truly random — they follow a set order each attempt. With practice, you can learn to dodge every pattern.

Rewards

• Pacifist victory: Jevilstail — a powerful armor that can be equipped by any party member.
• Violent victory: Devilsknife — a powerful weapon for Susie.
• Either way, you also receive the Chapter 1 Shadow Crystal.

Pre-Fight Checklist